1. Field
Methods and apparatuses consistent with exemplary embodiments relate to manufacturing a graphene sheet, the graphene sheet, and a device using the same.
2. Description of the Related Art
General graphite is a stack of two-dimensional graphene having a plate shape in which carbon atoms are connected to one another in a hexagonal shape.
Graphene has very useful properties different from those of existing materials. One remarkable property of graphene is that when electrons move in graphene, they move as if the mass of the electrons is zero. This means that the electrons move at a speed at which light moves in vacuum, that is, at the speed of light. The electron mobility of currently well-known graphene amounts to a maximum of 200,000 cm2/Vs. Graphene exhibits an abnormal half-integer quantum Hall effect with respect to electrons and holes, and exhibits a fractional quantum Hall effect when the graphene is suspended in the air.
Moreover, since the electrical properties of graphene vary according to the crystalline directivity of graphene having a given thickness, a user may provide an electrical property in a direction which the user selects, and thus, may easily design a device. Such electrical properties of graphene are compared with those of carbon natnotubes (CNT) whose metallic and semiconductive electrical properties vary according to the chirality and the diameter of the CNT. CNT should undergo separation, which is difficult, in order to use a particular semiconductor property and a particular metallic property. Moreover, graphene is economically favorable compared with CNT that undergoes refinement after synthesis. Therefore, graphene may be effectively used in carbon-based electric or electromagnetic devices and the like.
Examples of a graphene sheet manufacturing method include a micromechanical method and a SiC crystal pyrolysis method.
In the micromechanical method, a tape is attached to a graphite sample, and then, detached therefrom, thereby obtaining a graphene sheet, which is detached from the graphite sample, on the surface of the tape.
In the SiC crystal pyrolysis method, when SiC single crystal is heated, SiC on the surface of SiC single crystal is decomposed and Si is removed, and then, a graphene sheet is obtained from carbon (C).